Researchers at the University of Chile have developed two working prototypes of Koala 3D, a free-form “climbing” 3D printer with an unlimited Z-axis. The unusual 3D printer can climb the object it is currently printing in the same way a koala climbs a tree.

Over the years, there have been a handful of clever tricks for extending an axis (or axes) of a 3D printer, allowing for larger or even unlimited 3D printing in one direction.

In May 2017, for example, we learned that a Dutch 3D printing company called Blackbelt 3D had developed a conveyor belt 3D printer for continuous FDM 3D printing. The idea was that, by replacing a print bed with a moving conveyor belt, you could print endlessly as the bed moved on and on, making either very long structures or an endless queue of smaller items.

There have been other innovations too. In 2015, an engineer created the Kickstarter-backed Z-Unlimited, a modification for Ultimaker 3D printers that “flips your 3D printer upside down and moves it all the way up along a wall while it is printing.” The accessory’s largest “Skyscraper” version enabled a gargantuan 3050 mm printing height.

So how else can you get long, wide, or deep 3D printing without simply buying a much larger, more expensive 3D printer?

Researchers at the University of Chile have come up with a new solution, and it’s possibly the most fun innovation of the lot: a climbing 3D printing robot that shimmies up the object it is printing like a koala climbs a tree.

Koala Z-Infinity 3D printer

“The goal of this project is to develop a new type of 3D printing machine capable of producing vertical structures while simultaneously climbing the same structures they build,” explains Juan Cristobal Zagal, chief designer of Koala 3D. “In principle, this type of machine might be capable of printing without limit on the vertical axis, becoming what can be called a Z-infinity 3D printing climbing machine.”

Sounds fascinating, but how does a Z-infinity 3D printing climbing machine work?

The researchers—Zagal, Maximiliano Velez, and Efren Toala—say they have actually developed two versions of the 3D printer: the Koala and the Toala (the latter being principally engineered by the appropriately named Mr. Toala).

The first of those climbing 3D printers, the Koala, is able to climb a vertical 30 x 30 mm column by grasping it, just like a koala grabs and climbs up a tree. The 3D printer 3D prints this column as it ascends, simultaneously 3D printing the actual 3D printed object within the walls of the climbing column. (The 3D printed object can then be extracted from the hollow column when printing is finished.)

Two clamping carriages serve to grip and propel the 3D printing unit while also controlling the Z position of the print head, while a counterbalance positions the center of mass in the middle of the column.

Toala Z-Infinity 3D printer

The second climbing 3D printer, the Toala, is slightly different, using a simpler mechanism to climb upward as it prints. Instead of printing a tree-like column and shimmying up it, this printer prints a kind of stepped ladder column, then uses a motorized pinion to “drive” up the column as it prints.

Needless to say, these 3D printing systems demonstrate a brilliant ability to think outside the box, and they will soon be even better: the researchers say they will be able to significantly widen the printed columns, which means the Koala could 3D print objects beyond very tall and narrow ones.